Horse or deer fly?
Over the years I have seen this insect in the summer. Only about one or two a year. It has a strange wingspan, like an F-15 fighter jet wing, no separation. It is black with white polka dots on the wings. Size of a small moth. Yesterday I had one sting/bite me. Feels like a bee sting, still hurts, itches, swollen and skin is warm to touch in that area. I have searched the web to identify this bug with no luck. Any ideas on what it is? If I can get a photo of one I’ll send it.
It sounds like you are dealing with deer flies. They have the wing shape you describe. Control is generally not feasible due to the habits of these flies. Insect repellents may be effective in preventing the painful bites by the females.